Method of making brake drums



Aug. 20, 1935. WA. MULHERN I METHOD OF MAKING BRAKE DRUMS Original Filed July 29, 1931 i if H a c ijJ 21- ADI INVENTOR. WILLIAM A.MULHERN.

BY E ATTORNEYS.

Patented Au 20,1935

METHODOF MAKING BRAKE DRUMS William A. Mulhern, Detroit, Mich, assignor to Chrysler Corporation, poration of Delaware Detroit, Mich, a cororiginalapplication July 29, 1931, Serial'No. 553,769. Divided and this application May 3,

1933, Serial No. 669,111

' 1Claim.

' lining, cast integral with an external web and drum wherein heat is concentrated during brak- 2-2 of Fig. 1,

t ing operations for permitting the escapement of operation and it includes a, cylindrical part 1 r having apertures 2 extending through its intermediate portion, and a side wall 3 which is providedwith a centralopening 4 for receiving a hub structure of aiwheel; Formed in the inner portion of the sidewall 3 are apertures 5 through which bolts, not shown, are extended for rigidly securing the drum to the wheel. Spaced aper- 'tures, or slots 6 are provided in the drum at the junction of the side wall 3 and cylindrical portions I for permitting air which is heated during braking operations to escape'from the interior of the drum. g e

The inner periphery of the drum is provided with a continuous lining 1 having a cylindrical surface 8 against which brake shoes 9 operate.

The brake shoes 9 are pivotally mounted on a lug ID that is carried by the axle of the wheel with which the brake drum is associated and they are adapted to be urged outwardly by con i shown).

allyextending flange or web ll -Which is integrally connected with the lining l by metal necks 12 which extend through the apertures 2.

The inner lining and outer web are preferably formed of cast iron and they are simultaneously cast upon the cylindrical portion of the drum in any conventional manner. This simultaneous V casting of the inner lining and outer web may,

be performed by placing the die cast sheet steel drum in a mold of the type illustratedin Fig. 3 which is provided with an annular chamber l3 adjacent the, inner periphery of the cylindrical portion of the drum and an annular chamber I4 adjacent the outer periphery of the cylindrical portion 1. The annular chambers l3 and I4 communicate with each other through the openings 2 in the cylindrical part of the drum which permit integral fusion of the molten metal that is introduced into the inner annular chamber l3 with the molten metal introduced into the outer annular chamber M. The molten metal may be poured into either one of the chambers and then allowed to flow into the other chamber, or it may be poured directly into both chambers.

The outer web H dissipates the heat which is, created in the drum during braking operations into the atmosphere and the integral necks l2 between the inner lining and the outer web provide efiicient conduction of heat from the inner lining to the web.

Although but one specific embodiment of this invention has herein been shown and described, it will be understood that various changes in the size, shape and arrangement of parts may be made without departing from the spirit of my invention and it is not my intention to limit its scope other than by the terms of the appended claim.

What I claim is: r 1 1 The methodof making a composite pressed 1 metaland cast metal brake drum which consists 40 inprcviding on opposite sides of the peripheral flange of a pressed brake drum shell chambers having spaced interconnected passages throughout said flange and completely surrounded by the metal of the latter, and filling said chambers and said interconnected passages with molten metal so as to form on one side of said shella lining of cast metal conforming to the contour of the adjacent surface thereof and an outwardly extending peripheral web on the opposite side of said shell integral with said cast metal lining whereby a mechanical interlock is provided for holding said cast metal portion against movement in all directions relative to said shell.

WILLIAM A. MULHERN. 

